Cancer of the prostate is the most prevalent malignancy in adult males, excluding skin cancer, and is an increasingly prevalent health problem in the United States. In 1996, it was estimated that 41,400 deaths would result from this disease in the United States alone, indicating that prostate cancer is second only to lung cancer as the most common cause of death in the same population. If diagnosed and treated early, when the cancer is still confined to the prostate, the chances of cure is significantly higher.
Treatment decisions for an individual are linked to the stage of prostate cancer present in that individual. A common classification of the spread of prostate cancer was developed by the American Urological Association (AUA). The AUA system divides prostate tumors into four stages, A to D. Stage A, microscopic cancer within prostate, is further subdivided into stages A1 and A2. Sub-stage A1 is a well-differentiated cancer confined to one site within the prostate. Treatment is generally observation, radical prostatectomy, or radiation. Sub-stage A2 is a moderately to poorly differentiated cancer at multiple sites within the prostate. Treatment is radical prostatectomy or radiation. Stage B, palpable lump within the prostate, is also further subdivided into sub-stages B1 and B2. In sub-stage B1, the cancer forms a small nodule in one lobe of the prostate. In sub-stage B2, the cancer forms large or multiple nodules, or occurs in both lobes of the prostate. Treatment for sub-stages B1 and B2 is either radical prostatectomy or radiation. Stage C is a large cancer mass involving most or all of the prostate and is also further subdivided into two sub-stages. In sub-stage C1, the cancer forms a continuous mass that may have extended beyond the prostate. In sub-stage C2, the cancer forms a continuous mass that invades the surrounding tissue. Treatment for both these sub-stages is radiation with or without drugs to address the cancer. The fourth stage, Stage D is metastatic cancer and is also subdivided into two sub-stages. In sub-stage D1, the cancer appears in the lymph nodes of the pelvis. In sub-stage D2, the cancer involves tissues beyond lymph nodes. Treatment for both of these sub-stages is systemic drugs to address the cancer as well as pain.
However, current prostate cancer staging methods are limited. As many as 50% of prostate cancers initially staged as A2, B, or C are actually stage D, metastatic. Discovery of metastasis is significant because patients with metastatic cancers have a poorer prognosis and require significantly different therapy than those with localized cancers. The five year survival rates for patients with localized and metastatic prostate cancers are 93% and 29%, respectively.
Accordingly, there is a great need for more sensitive and accurate methods for the staging of a cancer in a human to determine whether or not such cancer has metastasized and for monitoring the progress of a cancer in a human which has not metastasized for the onset of metastasis.
Three genes have now been identified as diagnostic arkers for prostate cancer. These diagnostic markers are referred to herein generally as cancer specific genes or CSGs and more specifically as Pro119, Pro121 and Pro124. The nucleotide sequence of Pro119 shares 91% homology with a rat G-protein coupled receptor (Raming et al. Receptor Channels 1998 6(2):141-51). ESTs for these CSGs are set forth as SEQ ID NO: 1, 3 and 5 while the full length contigs for these CSGs are set forth in SEQ ID NO: 2, 4 and 6, respectively. An exemplary protein encoded by Pro119 (SEQ ID NO:1 or 2) is depicted herein as SEQ ID NO:7.
In the present invention, methods are provided for detecting, diagnosing, monitoring, staging, prognosticating, imaging and treating prostate cancer via the cancer specific genes referred to herein as CSGs. For purposes of the present invention, CSG refers, among other things, to native protein expressed by the gene comprising a polynucleotide sequence of SEQ ID NO:1, 2, 3, 4, 5 or 6. An exemplary protein encoded by Pro119 (SEQ ID NO:1 or 2) is depicted herein as SEQ ID NO:7. By “CSG” it is also meant herein polynucleotides which, due to degeneracy in genetic coding, comprise variations in nucleotide sequence as compared to SEQ ID NO: 1-6, but which still encode the same protein. In the alternative, what is meant by CSG as used herein, means the native mRNA encoded by the gene comprising the polynucleotide sequence of SEQ ID NO:1, 2, 3, 4, 5 or 6, levels of the gene comprising the polynucleotide sequence of SEQ ID NO:1, 2, 3, 4, 5 or 6, or levels of a polynucleotide which is capable of hybridizing under stringent conditions to the antisense sequence of SEQ ID NO:1, 2, 3, 4, 5 or 6.
Other objects, features, advantages and aspects of the present invention will become apparent to those of skill in the art from the following description. It should be understood, however, that the following description and the specific examples, while indicating preferred embodiments of the invention are given by way of illustration only. Various changes and modifications within the spirit and scope of the disclosed invention will become readily apparent to those skilled in the art from reading the following description and from reading the other parts of the present disclosure.